Recently, a stage apparatus that transports a target transport object mounted on a table and positions the target transport object at a predetermined position is used for a precision machining apparatus and a precision measuring instrument as well as a drawing apparatus and an exposure apparatus used in semiconductor manufacturing processes. An aerostatic type air slide is usually used for a guide member included in this type of stage apparatus. Recently, an H-shaped air slide configured to arrange X and Y axes in an H-shape on a stage base is also often used to achieve high precision and low profile.
However, the conventional stage apparatus including the H-shaped air slide has had the following problem. That is, in the conventional H-shaped air slide, two Y-axis air slides are arranged parallel to each other and spaced apart from each other by a predetermined distance, and both end surfaces of an X-axis shaft included in an X-axis air slide are directly connected by a bolt or the like to side surfaces of Y-axis slides respectively included in the two Y-axis air slides. Therefore, when the two Y-axis sliders are separately driven, displacement during control is directly propagated to the Y-axis sliders. Consequently, there occurs the problem that attitude precision of rotation around Z direction, namely yawing, is deteriorated, and the Y-axis sliders and the X-axis square shaft are contacted with each other to cause scoring.
In order to solve the above problem, patent document 1 discloses an X-Y stage apparatus including a Y slider whose one end extends in an X-axis direction as a free end.
However, the X-Y stage apparatus described in the patent document 1 has the problem that the rigidity of the free end side of the Y slider is low and hence yawing attitude precision is deteriorated during acceleration and deceleration. The X-Y stage apparatus described in the patent document 1 also has the problem of being prone to oscillations because fundamental frequency differs depending on the location of the Y slider.